I recently aquired a used GPR .54 rifle. It has quite a bit of surface rust in the bore which was bothersome but I managed to clean it up. I was cleaning the nipple hole and noticed the clean out screw was in further than my other Lyman rifle. I was quite surprised that it screws in and out with very little difficulty. This is odd considering every thing else was crusty. I'm in the 'don't screw with the screw' camp and am thinking about JB welding it in place. Shouldn't there be a stop that keeps it from screwing all the way into the drum? I'm worried it could be compromised and unsafe.